Maintenance Branches

The goal of this document is to describe and explain work-flow for maintenance
branches. It does not affect development in master except of merging of fixes from
maintenance branch. It is not goal of this document to discuss which way is better
for pull requests or how to use the git in exact situations.

Why Maintenance Branches?

YaST uses maintenance branches because it is easier to track patches for already
released products in git then in Build Service. It gives ability to easy review
of fixes and also to merge fixes in master branch, to avoid forgotten ones.

Maintenance Work-Flow

There is difference between older maintenance branches and new ones starting
from SLE-12-GA.

For older branches fix is created in separated commits. Command git cherry-pick
can be used, but to apply fix from ycp to ruby code is recommended to write it
from scratch. Also when backporting fix from ruby to ycp it is recommended to
write it from scratch as there is no ruby2ycp converter.

For new branches fix have to be done in the oldest affected branch and then
merged to newer branches and master with git merge. There are two reasons for
such change.
The first and main reason is that it allows easy tracking if fix in commit is
also in newer branches and master. The second reason is that it produces nicer
git tree structure which allows to see which code stream is affected by which
fix.

When maintenance fix was not requested and made only in master and then
requested to backport to a maintenance branch, it is still needed to merge back
the cherry-pick used for backporting the fix.
It is valid only for new branches.

Maintenance Fixes Rules

To get all benefits described above, there are few easy rules.

no cherry-pick as part of common work-flow. In a nutshell, cherry-picking
changes the SHA because the commit will get a new parent commit. And with
different SHAs, it is difficult to find out if all desired commits from the
branch are now also in master. For deeper explanation see these articles
1, 2 or reddit)

merge new maintenance branches to master regularly

create fix for the oldest applicable branch first

How to Submit a Maintenance Request

For master it is handled by Jenkins and no work is needed.

For branches that contain a Rakefile,
ensure that the version has been increased and call rake osc:sr.

For branches without a Rakefile, create the source tarball and follow the
openSUSE guide.

How to Create a Maintenance Branch

When a maintenance branch needs to be created, there is a
helper tool
available in devtools. Execute it without arguments to see usage instructions.

Maintenance Branch Naming

Already known names for branches:

SLE-10: SLE 10 GA

SLE-10-SP*: SLE 10 Service packs

Code-11: SLE 11 GA

Code-11-SP*: SLE 11 Service packs

SLE-12-GA: SLE 12 GA

SLE-12-SP*: SLE 12 Service packs

openSUSE-1*: respective openSUSE release

openSUSE-4*: openSUSE leap releases (see below)

Maintenance branches for Leap only make sense for a few repositories.
For most YaST packages, openSUSE Leap and SLE share the same code and
maintenance updates and, thus, only the corresponding SLE-* maintenance
branch is used. Leap maintenance branches will be created manually in a case by
case basis, only when needed and only for repositories that affect openSUSE but
not SLE.

How to find if maintenance branch is still actively maintained

NOTE: It uses SUSE internal tools, as it contain non public data about long term support.

Connect to DE network and run /work/src/bin/is_maintained <pkg_name>. If it failed, then to show
why osc failed, use -r which can indicate e.g. missing .oscrc file with credentials.